New innovations protecting lives in flood-prone Cambodia

Launched: June 2017

By James Happell, People in Need

Seasonal flooding is a perpetual challenge for the people of Cambodia, a country consistently ranked as one of the most vulnerable to the effects of natural disasters. Floods in 2013 covered almost half the country and affected nearly 1.7 million people. More than 50 people lost their lives and hundreds of thousands more were left homeless. If provided with advanced warning however, many of these people could have been helped.

In order to deliver timely and potentially lifesaving information to people in disaster prone areas, People in Need Cambodia have developed an Early Warning System ‘EWS 1294’ which delivers warning messages directly to the mobile phones of people at risk. 

In the event of a natural disaster, the National Committee for Disaster Management has been trained to send out audio messages to people in the affected areas warning them of potential risks. The system uses voice messages rather than text messages in order to include all Cambodians, regardless of any literacy issues.

First piloted in 2013, the system has now expanded to cover more than 200,000 households in seven provinces, including many of the most vulnerable areas of Cambodia.

Open Innovation

People in Need’s system would not be possible without the technology developed by programmes like the UNICEF Global Innovation Centre.

The system uses RapidPro, an open-source platform of applications that delivers rapid and vital real-time information, to manage the registration of users into the system. The interactive voice response platform Somleng (conceived by developer David Wilkie and supported by UNICEF’s Innovation Fund) is a cost effective means with which to connect important services like the early warning systems through to mobile phone carriers. The technology to provide this sort of assistance simply did not exist 10 years ago, and it is through the vision and innovation programs like UNICEF’s that these solutions have been made possible.

In order to strengthen the existing Early Warning System, People in Need has now developed an automated flood sensor named Tepmachcha, designed by the DAI Maker Lab with funding from USAID’s Development Innovations project. Tepmachcha is a solar-powered, GSM-enabled, sonar-based stream gauge, built on open-source technology.


The device uses ultrasonic sound waves to measure the height of the water and sends this captured data over the mobile phone network back to a centralized web application. If a dangerous ‘warning’ level of water is detected, the system automatically sends out a mobile alert message via People in Need’s Early Warning System.


Not only can this information be used to warn registered families of an impending flood, the data is also helping to provide long term insights into patterns of water levels in Cambodia, supporting the work of the National Flood Forecasting Centre.

Every minute is vital in a flooding scenario. Prior to the rollout of these devices, water monitoring was done manually and the time from detection to message dissemination could be hours, if not days. With the Tepmachcha sensors, warning messages are now sent to registered users almost instantly.

Early warnings allow people to prepare themselves, their families, and their livelihoods for the oncoming danger. This could mean evacuation to the nearest safe site, or staying in their homes and securing their most important possessions; the extra time to prepare can often mean the difference between life and death. New technology like RapidPro, Somleng and these Tepmachcha sensors, can help people avoid the worst outcomes when natural disasters strike.

Story originally appeared on UNICEF East Asia and Pacific Blog: